The invention relates to a texturing system, or a thread processing device, with a texturing nozzle for forming a textured thread. A nozzle of this generic type is described, for example, in the German published examined application 20 3 6856. The yarn, entering the nozzle from above, is conveyed by a hot-air flow to a compression part, which is provided with passage apertures, for example in slot form. Due to the lateral escape of the air being blown in, and as a result of the reduction in speed in the passage channel, the continuous filament yarn compresses, and thus also incurs a braking effect. The yarn strip which forms is ejected relatively slowly from the nozzle and cooled. In this situation, a rotating cooling drum can be used, on the surface of which the compressed yarn is laid, whereby, as a result of perforations in the drum, air at a lower temperature is sucked into the nozzle, e.g. ambient air, which has the effect of cooling the yarn.
The invention also relates to the compression part of a texturing system, in particular a BCF texturing nozzle, for high velocities. A compression part of a texturing nozzle according to the conventional design is usually formed from an upper and lower lamellar plate holder and a plurality of lamellar plates.
The texturing air and the yarn enter the compression part of high speed from above, i.e. in the direction of flow of the fibres and air respectively. The air flows in the area of the compression part in impart manner through the slots or intermediate spaces between the lamellar plates in a more or less radial direction, and mostly emerges to the outside at the lamellar plates. This has the effect of reducing the air speed in the longitudinal channel of the nozzle. The yarn is braked as a result and forms a strip, which fills the entire inner diameter of the slotted part, namely the compression part. The strip slides downwards through a strip guide tube to a cooling drum or to a conveying device, in particular a pair of rollers.
The strip formation inside the nozzle is influenced by the flow circumstances and geometric conditions which prevail there. If interruptions occur, or specific parameters on which the strip formation depends are altered, the quality of the thread may change impermissibly.
From U.S. Pat. No. 5,653,010, the principle is known of conducting the yarn strip from the texturing nozzle onto a drum and of steering the material flow on the circumferential surface thereof between two rows of needles, which project vertically from the surface. The strip formation in this situation, however, is only influenced at the transition point from the nozzle onto the drum by the conditions which prevail there, which in practice has not led to the desired consistent thread quality.
In EP Application No. 1101 849, it is proposed that the thread be deposited in a drum groove, in order thereby to control the conveyance of the strip better, and at the same time to cool in this situation, however, very narrow tolerances are to be maintained in the manufacture of the drum.